#include <SPI.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define BUZZER 8
#define TRIG 10
#define ECHO 9

#define SCREEN_WIDTH 128 // OLED display width,  in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels


Adafruit_SSD1306 oled(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);



void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);


  // Set buzzer
  pinMode(BUZZER, OUTPUT);

  // SETUP ULTRASONIC
  pinMode(TRIG, OUTPUT);
  pinMode(ECHO, INPUT);

  // SETUP OLED
  if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
      Serial.println(F("SSD1306 allocation failed"));
      while (true);
  }
  delay(1000);         // wait for initializing

}

void loop() {

  oled.clearDisplay();
  oled.setCursor(15, 10);
  oled.setTextSize(1);
  oled.setTextColor(WHITE);
  oled.print("Distance : ");

  int durasi;
  int jarak;

  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);
  durasi = pulseIn(ECHO, HIGH);
  jarak = (durasi/2) / 29.1;
  oled.print(jarak);
  oled.println(" cm");

  if (jarak <= 80) {
    tone(BUZZER, 800);
  } else if (jarak <= 200) {
    tone(BUZZER, 800);
    delay(150);
    noTone(BUZZER);
    delay(150);
  } else if (jarak <= 300) {
    tone(BUZZER, 800);
    delay(300);
    noTone(BUZZER);
    delay(300);
  } 


  oled.display();
  Serial.println(jarak);
}